If my custom WEC2013 OS image increases above 64MB do I need to change config.bib?

Technical Support
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1

Sometimes when changing from release to checked build the OS image gets rather large. Sometimes these images do not boot.

I was wondering if I would need to increase the ROM_SIZE in config.bib - if so, it is as simple as just changing it to an appropriate value? Does that also take up double the amount of memory, so reserves the OS in ROM, but it would also need the same amount of RAM to load and execute?

I’m using Colibri iMX6DL with WEC 2013.

Thanks!

2

You should increase size of NK region and decrease size of the RAM region accordingly.
The OS image will use the full amount of RAM on the module after boot, so the image should boot even if you defined a limited amount of memory in the RAM area.
So you have to increase NK size, shift beginning of RAM of the amount you used, decrease size of RAM so it ends at the same address as before.
Space not used by image will be anyway reclaimed back as regular RAM by the kernel.

3

So is that these values

#define NK_START    80200000
#define NK_SIZE     05E00000
#define RAM_START   86000000	
#define RAM_SIZE    04000000		; defined as minimum amount of 64MB to allocate video ram

So NK_SIZE is defined as 94MB? I shouldn’t really have any issues then if it’s just over 64MB?

4

Yes, it should work. The kernel maps statically 160MB (94+64+memory used by loader)